[PATCH 3/3] picolibc: Add '--oslib=' option when default C library is picolibc

This option allows targets to insert an OS library after the C library in the LIB_PATH spec file fragment. This library maps a few POSIX APIs used by picolibc to underlying system capabilities. For example, picolibc provides 'libsemihost' on various targets which maps these APIs to semihosting

[PATCH 3/3] picolibc: Add '--oslib=' option when default C library is picolibc

This option allows targets to insert an OS library after the C library in the LIB_PATH spec file fragment. This library maps a few POSIX APIs used by picolibc to underlying system capabilities. For example, picolibc provides 'libsemihost' on various targets which maps these APIs to semihosting